[PATCH] RTC: add rtc-ds1553 driver
Atsushi Nemoto [Sun, 25 Jun 2006 12:48:28 +0000 (05:48 -0700)]
Add an RTC driver for the Dallas DS1553 RTC chip.

[akpm@osdl.org: cleanups, compile fix]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-ds1553.c [new file with mode: 0644]

index 0bfd3aa..40e3d9c 100644 (file)
@@ -111,6 +111,16 @@ config RTC_DRV_DS1307
          This driver can also be built as a module. If so, the module
          will be called rtc-ds1307.
 
+config RTC_DRV_DS1553
+       tristate "Dallas DS1553"
+       depends on RTC_CLASS
+       help
+         If you say yes here you get support for the
+         Dallas DS1553 timekeeping chip.
+
+         This driver can also be built as a module. If so, the module
+         will be called rtc-ds1553.
+
 config RTC_DRV_DS1672
        tristate "Dallas/Maxim DS1672"
        depends on RTC_CLASS && I2C
index f39992b..1c50687 100644 (file)
@@ -19,6 +19,7 @@ obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
 obj-$(CONFIG_RTC_DRV_PCF8583)  += rtc-pcf8583.o
 obj-$(CONFIG_RTC_DRV_RS5C372)  += rtc-rs5c372.o
 obj-$(CONFIG_RTC_DRV_M48T86)   += rtc-m48t86.o
+obj-$(CONFIG_RTC_DRV_DS1553)   += rtc-ds1553.o
 obj-$(CONFIG_RTC_DRV_EP93XX)   += rtc-ep93xx.o
 obj-$(CONFIG_RTC_DRV_SA1100)   += rtc-sa1100.o
 obj-$(CONFIG_RTC_DRV_VR41XX)   += rtc-vr41xx.o
diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c
new file mode 100644 (file)
index 0000000..ecafbad
--- /dev/null
@@ -0,0 +1,414 @@
+/*
+ * An rtc driver for the Dallas DS1553
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/bcd.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#define DRV_VERSION "0.1"
+
+#define RTC_REG_SIZE           0x2000
+#define RTC_OFFSET             0x1ff0
+
+#define RTC_FLAGS              (RTC_OFFSET + 0)
+#define RTC_SECONDS_ALARM      (RTC_OFFSET + 2)
+#define RTC_MINUTES_ALARM      (RTC_OFFSET + 3)
+#define RTC_HOURS_ALARM                (RTC_OFFSET + 4)
+#define RTC_DATE_ALARM         (RTC_OFFSET + 5)
+#define RTC_INTERRUPTS         (RTC_OFFSET + 6)
+#define RTC_WATCHDOG           (RTC_OFFSET + 7)
+#define RTC_CONTROL            (RTC_OFFSET + 8)
+#define RTC_CENTURY            (RTC_OFFSET + 8)
+#define RTC_SECONDS            (RTC_OFFSET + 9)
+#define RTC_MINUTES            (RTC_OFFSET + 10)
+#define RTC_HOURS              (RTC_OFFSET + 11)
+#define RTC_DAY                        (RTC_OFFSET + 12)
+#define RTC_DATE               (RTC_OFFSET + 13)
+#define RTC_MONTH              (RTC_OFFSET + 14)
+#define RTC_YEAR               (RTC_OFFSET + 15)
+
+#define RTC_CENTURY_MASK       0x3f
+#define RTC_SECONDS_MASK       0x7f
+#define RTC_DAY_MASK           0x07
+
+/* Bits in the Control/Century register */
+#define RTC_WRITE              0x80
+#define RTC_READ               0x40
+
+/* Bits in the Seconds register */
+#define RTC_STOP               0x80
+
+/* Bits in the Flags register */
+#define RTC_FLAGS_AF           0x40
+#define RTC_FLAGS_BLF          0x10
+
+/* Bits in the Interrupts register */
+#define RTC_INTS_AE            0x80
+
+struct rtc_plat_data {
+       struct rtc_device *rtc;
+       void __iomem *ioaddr;
+       unsigned long baseaddr;
+       unsigned long last_jiffies;
+       int irq;
+       unsigned int irqen;
+       int alrm_sec;
+       int alrm_min;
+       int alrm_hour;
+       int alrm_mday;
+};
+
+static int ds1553_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+       void __iomem *ioaddr = pdata->ioaddr;
+       u8 century;
+
+       century = BIN2BCD((tm->tm_year + 1900) / 100);
+
+       writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);
+
+       writeb(BIN2BCD(tm->tm_year % 100), ioaddr + RTC_YEAR);
+       writeb(BIN2BCD(tm->tm_mon + 1), ioaddr + RTC_MONTH);
+       writeb(BIN2BCD(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
+       writeb(BIN2BCD(tm->tm_mday), ioaddr + RTC_DATE);
+       writeb(BIN2BCD(tm->tm_hour), ioaddr + RTC_HOURS);
+       writeb(BIN2BCD(tm->tm_min), ioaddr + RTC_MINUTES);
+       writeb(BIN2BCD(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
+
+       /* RTC_CENTURY and RTC_CONTROL share same register */
+       writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
+       writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
+       return 0;
+}
+
+static int ds1553_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+       void __iomem *ioaddr = pdata->ioaddr;
+       unsigned int year, month, day, hour, minute, second, week;
+       unsigned int century;
+
+       /* give enough time to update RTC in case of continuous read */
+       if (pdata->last_jiffies == jiffies)
+               msleep(1);
+       pdata->last_jiffies = jiffies;
+       writeb(RTC_READ, ioaddr + RTC_CONTROL);
+       second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
+       minute = readb(ioaddr + RTC_MINUTES);
+       hour = readb(ioaddr + RTC_HOURS);
+       day = readb(ioaddr + RTC_DATE);
+       week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
+       month = readb(ioaddr + RTC_MONTH);
+       year = readb(ioaddr + RTC_YEAR);
+       century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
+       writeb(0, ioaddr + RTC_CONTROL);
+       tm->tm_sec = BCD2BIN(second);
+       tm->tm_min = BCD2BIN(minute);
+       tm->tm_hour = BCD2BIN(hour);
+       tm->tm_mday = BCD2BIN(day);
+       tm->tm_wday = BCD2BIN(week);
+       tm->tm_mon = BCD2BIN(month) - 1;
+       /* year is 1900 + tm->tm_year */
+       tm->tm_year = BCD2BIN(year) + BCD2BIN(century) * 100 - 1900;
+
+       if (rtc_valid_tm(tm) < 0) {
+               dev_err(dev, "retrieved date/time is not valid.\n");
+               rtc_time_to_tm(0, tm);
+       }
+       return 0;
+}
+
+static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
+{
+       void __iomem *ioaddr = pdata->ioaddr;
+       unsigned long flags;
+
+       spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
+       writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
+              0x80 : BIN2BCD(pdata->alrm_mday),
+              ioaddr + RTC_DATE_ALARM);
+       writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
+              0x80 : BIN2BCD(pdata->alrm_hour),
+              ioaddr + RTC_HOURS_ALARM);
+       writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
+              0x80 : BIN2BCD(pdata->alrm_min),
+              ioaddr + RTC_MINUTES_ALARM);
+       writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
+              0x80 : BIN2BCD(pdata->alrm_sec),
+              ioaddr + RTC_SECONDS_ALARM);
+       writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
+       readb(ioaddr + RTC_FLAGS);      /* clear interrupts */
+       spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
+}
+
+static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+
+       if (pdata->irq < 0)
+               return -EINVAL;
+       pdata->alrm_mday = alrm->time.tm_mday;
+       pdata->alrm_hour = alrm->time.tm_hour;
+       pdata->alrm_min = alrm->time.tm_min;
+       pdata->alrm_sec = alrm->time.tm_sec;
+       if (alrm->enabled)
+               pdata->irqen |= RTC_AF;
+       ds1553_rtc_update_alarm(pdata);
+       return 0;
+}
+
+static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+
+       if (pdata->irq < 0)
+               return -EINVAL;
+       alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
+       alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
+       alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
+       alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
+       alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
+       return 0;
+}
+
+static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id,
+                                       struct pt_regs *regs)
+{
+       struct platform_device *pdev = dev_id;
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+       void __iomem *ioaddr = pdata->ioaddr;
+       unsigned long events = RTC_IRQF;
+
+       /* read and clear interrupt */
+       if (!(readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF))
+               return IRQ_NONE;
+       if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
+               events |= RTC_UF;
+       else
+               events |= RTC_AF;
+       rtc_update_irq(&pdata->rtc->class_dev, 1, events);
+       return IRQ_HANDLED;
+}
+
+static void ds1553_rtc_release(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+
+       if (pdata->irq >= 0) {
+               pdata->irqen = 0;
+               ds1553_rtc_update_alarm(pdata);
+       }
+}
+
+static int ds1553_rtc_ioctl(struct device *dev, unsigned int cmd,
+                           unsigned long arg)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+
+       if (pdata->irq < 0)
+               return -ENOIOCTLCMD;
+       switch (cmd) {
+       case RTC_AIE_OFF:
+               pdata->irqen &= ~RTC_AF;
+               ds1553_rtc_update_alarm(pdata);
+               break;
+       case RTC_AIE_ON:
+               pdata->irqen |= RTC_AF;
+               ds1553_rtc_update_alarm(pdata);
+               break;
+       case RTC_UIE_OFF:
+               pdata->irqen &= ~RTC_UF;
+               ds1553_rtc_update_alarm(pdata);
+               break;
+       case RTC_UIE_ON:
+               pdata->irqen |= RTC_UF;
+               ds1553_rtc_update_alarm(pdata);
+               break;
+       default:
+               return -ENOIOCTLCMD;
+       }
+       return 0;
+}
+
+static struct rtc_class_ops ds1553_rtc_ops = {
+       .read_time      = ds1553_rtc_read_time,
+       .set_time       = ds1553_rtc_set_time,
+       .read_alarm     = ds1553_rtc_read_alarm,
+       .set_alarm      = ds1553_rtc_set_alarm,
+       .release        = ds1553_rtc_release,
+       .ioctl          = ds1553_rtc_ioctl,
+};
+
+static ssize_t ds1553_nvram_read(struct kobject *kobj, char *buf,
+                                loff_t pos, size_t size)
+{
+       struct platform_device *pdev =
+               to_platform_device(container_of(kobj, struct device, kobj));
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+       void __iomem *ioaddr = pdata->ioaddr;
+       ssize_t count;
+
+       for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
+               *buf++ = readb(ioaddr + pos++);
+       return count;
+}
+
+static ssize_t ds1553_nvram_write(struct kobject *kobj, char *buf,
+                                 loff_t pos, size_t size)
+{
+       struct platform_device *pdev =
+               to_platform_device(container_of(kobj, struct device, kobj));
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+       void __iomem *ioaddr = pdata->ioaddr;
+       ssize_t count;
+
+       for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
+               writeb(*buf++, ioaddr + pos++);
+       return count;
+}
+
+static struct bin_attribute ds1553_nvram_attr = {
+       .attr = {
+               .name = "nvram",
+               .mode = S_IRUGO | S_IWUGO,
+               .owner = THIS_MODULE,
+       },
+       .size = RTC_OFFSET,
+       .read = ds1553_nvram_read,
+       .write = ds1553_nvram_write,
+};
+
+static int __init ds1553_rtc_probe(struct platform_device *pdev)
+{
+       struct rtc_device *rtc;
+       struct resource *res;
+       unsigned int cen, sec;
+       struct rtc_plat_data *pdata = NULL;
+       void __iomem *ioaddr = NULL;
+       int ret = 0;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return -ENODEV;
+       pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+       if (!pdata)
+               return -ENOMEM;
+       pdata->irq = -1;
+       if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
+               ret = -EBUSY;
+               goto out;
+       }
+       pdata->baseaddr = res->start;
+       ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE);
+       if (!ioaddr) {
+               ret = -ENOMEM;
+               goto out;
+       }
+       pdata->ioaddr = ioaddr;
+       pdata->irq = platform_get_irq(pdev, 0);
+
+       /* turn RTC on if it was not on */
+       sec = readb(ioaddr + RTC_SECONDS);
+       if (sec & RTC_STOP) {
+               sec &= RTC_SECONDS_MASK;
+               cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
+               writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
+               writeb(sec, ioaddr + RTC_SECONDS);
+               writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
+       }
+       if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
+               dev_warn(&pdev->dev, "voltage-low detected.\n");
+
+       if (pdata->irq >= 0) {
+               writeb(0, ioaddr + RTC_INTERRUPTS);
+               if (request_irq(pdata->irq, ds1553_rtc_interrupt, SA_SHIRQ,
+                               pdev->name, pdev) < 0) {
+                       dev_warn(&pdev->dev, "interrupt not available.\n");
+                       pdata->irq = -1;
+               }
+       }
+
+       rtc = rtc_device_register(pdev->name, &pdev->dev,
+                                 &ds1553_rtc_ops, THIS_MODULE);
+       if (IS_ERR(rtc)) {
+               ret = PTR_ERR(rtc);
+               goto out;
+       }
+       pdata->rtc = rtc;
+       pdata->last_jiffies = jiffies;
+       platform_set_drvdata(pdev, pdata);
+       sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
+       return 0;
+ out:
+       if (pdata->irq >= 0)
+               free_irq(pdata->irq, pdev);
+       if (ioaddr)
+               iounmap(ioaddr);
+       if (pdata->baseaddr)
+               release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
+       kfree(pdata);
+       return ret;
+}
+
+static int __devexit ds1553_rtc_remove(struct platform_device *pdev)
+{
+       struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
+
+       sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
+       rtc_device_unregister(pdata->rtc);
+       if (pdata->irq >= 0) {
+               writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
+               free_irq(pdata->irq, pdev);
+       }
+       iounmap(pdata->ioaddr);
+       release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
+       kfree(pdata);
+       return 0;
+}
+
+static struct platform_driver ds1553_rtc_driver = {
+       .probe          = ds1553_rtc_probe,
+       .remove         = __devexit_p(ds1553_rtc_remove),
+       .driver         = {
+               .name   = "ds1553",
+               .owner  = THIS_MODULE,
+       },
+};
+
+static __init int ds1553_init(void)
+{
+       return platform_driver_register(&ds1553_rtc_driver);
+}
+
+static __exit void ds1553_exit(void)
+{
+       return platform_driver_unregister(&ds1553_rtc_driver);
+}
+
+module_init(ds1553_init);
+module_exit(ds1553_exit);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);